Duluth flood: Lake Superior looks like it was infused with chocolate milk [PHOTOS]

Following the flood, some boaters have reported seeing entire trees floating in Lake Superior.

The effects of last month's unprecedented flooding can be seen in aerial shots of Lake Superior, which show chocolate milk-colored waters stretching all the way from the Twin Ports to Wisconsin's Chequamegon Bay.

Erik Brown, acting director of the Large Lakes Observatory at the University of Minnesota Duluth, told the Duluth News-Tribune that photos showing a brown ring along Superior's western shore are "unprecedented, really... No one I've talked to has ever seen the lake like this."

"And it wasn't just on the top," Brown added. "We had people out on the water taking samples and it was the same right down to the bottom at 100 feet deep. They were recording zero light penetration from the top to the bottom."

Brown said copepods, tiny creatures that usually rise out of the water's depths only at night, have been seen swimming around during the middle of the day in the wake of the June 20 flood.

"They thought it was night," he said.

It's unclear what impact the infusion of flood waters might have on the lake's ecosystem. Josh Blankenheim, DNR fisheries specialist, said one worry is that settling clay might cover up trout spawning reefs and make them unsuitable for eggs to properly incubate and hatch. Another concern is that much of the sediment swept into the lake carries pesticides.

But "we don't really have any research that tells us what's going on down there," Blankenheim said.

Here's a photo from just a day or two after the flood showing how brown Lake Superior's waters were in the Duluth-Superior area: